Negative thermal expansion current interrupter

ABSTRACT

An electric power system such as, for example, a circuit, an electric appliance, an electric generator, and/or an energy storage system, can be coupled with a negative thermal expansion component. The negative thermal expansion component can be formed from a material having negative thermal expansion properties such that the negative thermal expansion component contracts in response to an increase in temperature. The contraction of the negative thermal expansion component can form a nonconductive gap that disrupts current flow through the electric power system. The disruption of the current flow can eliminate hazards associated with the electric power system overcharging, overheating, and/or developing an internal short circuit.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/492,827 filed on May 1, 2017 and entitled BATTERY WITH INTERNALNEGATIVE THERMAL EXPANSION CURRENT INTERRUPTER, the disclosure of whichis incorporated herein by reference in its entirety.

TECHNICAL FIELD

The subject matter described herein relates generally to electric powersystems and more specifically to a negative thermal expansion currentinterrupter for electric power systems.

BACKGROUND

An electric power system can encounter a number of risks duringoperation including, for example, overheating, overcharging, shortcircuiting, and/or the like. For instance, overcurrent can refer to asituation in which a larger than intended current flows through anelectric power system such as, for example, a circuit, an electricappliance, an electric generator, an energy storage system, and/or thelike. Overcurrent can occur due to current overload, short circuits,design flaws, ground faults, arc faults, and/or the like. The heatgenerated by the excess current can pose significant risks including,for example, fires, explosions, and damage to the electric power system.

SUMMARY

Systems, methods, and articles of manufacture, including batteries andbattery components, are provided. In some implementations of the currentsubject matter, there is provided a battery. The battery can include afirst current interrupter. The first current interrupter can include anegative thermal expansion material such that the first currentinterrupter contracts in response to an increase in temperature. Thecontraction of the first current interrupter can form a nonconductivegap within the battery. The formation of the nonconductive gap candisrupt a current flow within the battery.

In some variations, one or more features disclosed herein including thefollowing features can optionally be included in any feasiblecombination. The battery can further include a first electrode. Thefirst current interrupter can be disposed on a surface of the firstelectrode.

In some variations, the battery can further include a current collector.The first current interrupter can be interposed between the firstelectrode and the current collector. The formation of the nonconductivegap can disrupt the current flow at least by electrically decoupling thefirst electrode and the current collector.

In some variations, the battery can further include a second electrodeand a second current interrupter. The second current interrupter can beinterposed between the first electrode and the second electrode. Thesecond interrupter can include the negative thermal material such thatthe second current interrupter contracts in response to the increase intemperature. The contraction of the second current interrupter can formanother nonconductive gap within the battery. The formation of the othernonconductive gap can further disrupt the current flow at least byelectrically decoupling the first electrode and the second electrode.

In some variations, the battery can further include a separator. Thecurrent interrupter can be interposed between the separator and thefirst electrode. The formation of the nonconductive gap can disrupt thecurrent flow at least by electrically decoupling the separator and thefirst electrode.

In some variations, the negative thermal expansion material can includeone or more oxides. The negative thermal expansion material can includea silicate, a zirconium tungstate, a cyanide, a ruthenate, a siliceousfaujasite, Fe₃Pt, a perovskite oxides, an antiperovskite, a zeolite, asamarium fulleride, LaCu₃Fe₄O₁₂, an invar alloy, a metal oxide, alow-dimensional material, a metal fluoride, a mechanoresponsive polymer,a porous polyacrylamide, a dibenzocyclooctadiene (DBCOD), and/or apolyacrylamide film containing dibenzocyclooctadiene (DBCOD). Thenegative thermal expansion material can include a composite of one ormore negative thermal expansion materials.

In some variations, the first electrode can be a cathode or an anode ofthe battery. The first electrode can include lithium (Li).

In some implementations of the current subject matter, there is provideda fuse. The fuse can include a negative thermal expansion plateinterposed between a first metal plate and a second metal plate. Thenegative thermal expansion plate can include a negative thermalexpansion material such that at least a portion of the negative thermalexpansion plate can contract in response to an increase in temperature.The contraction of the negative thermal expansion plate can form anonconductive gap between the first metal plate and the second metalplate. The formation of the nonconductive gap can disrupt a current flowthrough an electric power system coupled with the fuse.

In some variations, the negative thermal expansion plate can include anonconductive material configured to provide structural support. Thenonconductive material can include a positive temperature coefficientmaterial such that another portion of the negative thermal expansionplate undergoes a phase transition in response to a temperatureexceeding a threshold value. The phase transition can cause the otherportion of the negative thermal expansion plate to expand. Thenonconductive gap can be further formed by the expansion of the otherportion of the negative thermal expansion plate.

In some variations, the positive temperature coefficient material caninclude poly ethylene, polyvinylidene fluoride (PVDF), acrylonitrilebutadiene styrene (ABS) thermoplastic, glass and/or fiber-reinforcedacrylonitrile butadiene styrene (ABS), acetal, amber, benzocyclobutene,cellulose acetate (CA), cellulose acetate butynate (CAB), cellulosenitrate (CN), chlorinated polyether, chlorinated polyvinylchloride(CPVC), ethylene ethyl acrylate (EEA), ethylene vinyl acetate (EVA),fluoroethylene propylene (FEP), fluorspar, CaF₂, gutta percha, nylonmolding and/or extruding compound, paraffin, polybutylene (PB),polyamide (PA), polyester, and/or polypropylene (PP).

In some variations, the electric power system can be a circuit, anelectric appliance, an electric generator, and/or an energy storagesystem. The fuse can be disposed on an interior of the electric powersystem. The fuse can be coupled with the electric power system via anexternal connection.

In some variations, the negative thermal expansion material can includeone or more oxides. The negative thermal expansion material can includea silicate, a zirconium tungstate, a cyanide, a ruthenate, a siliceousfaujasite, Fe₃Pt, a perovskite oxides, an antiperovskite, a zeolite, asamarium fulleride, LaCu₃Fe₄O₁₂, an invar alloy, a metal oxide, alow-dimensional material, a metal fluoride, a mechanoresponsive polymer,a porous polyacrylamide, a dibenzocyclooctadiene (DBCOD), and/or apolyacrylamide film containing dibenzocyclooctadiene (DBCOD). Thenegative thermal expansion material can include a composite of one ormore negative thermal expansion materials.

The details of one or more variations of the subject matter describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features and advantages of the subject matter describedherein will be apparent from the description and drawings, and from theclaims. While certain features of the currently disclosed subject matterare described for illustrative purposes in relation to web applicationuser interfaces, it should be readily understood that such features arenot intended to be limiting. The claims that follow this disclosure areintended to define the scope of the protected subject matter.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, show certain aspects of the subject matterdisclosed herein and, together with the description, help explain someof the principles associated with the disclosed implementations. In thedrawings,

FIG. 1 depicts a schematic diagram illustrating an example of a batterycell having a negative thermal expansion component consistent withimplementations of the current subject matter;

FIG. 2 depicts a schematic diagram illustrating another example of abattery cell having a negative thermal expansion component consistentwith implementations of the current subject matter;

FIG. 3 depicts a schematic diagram illustrating another example of abattery cell having a negative thermal expansion component consistentwith implementations of the current subject matter;

FIG. 4A depicts a schematic diagram illustrating a negative thermalexpansion fuse coupled with an electric power system consistent withimplementations of the current subject matter;

FIG. 4B depicts a cross sectional view an example of a negative thermalexpansion fuse consistent with implementations of the current subjectmatter;

FIG. 4C depicts an exploded view of an example of a negative thermalexpansion fuse consistent with implementations of the current subjectmatter;

FIG. 5 depicts a schematic diagram illustrating a hybrid negativethermal expansion component consistent with implementations of thecurrent subject matter;

FIG. 6 depicts a flowchart illustrating a process for preparing anelectrode layered with a negative thermal expansion component consistentwith implementations of the current subject matter;

FIG. 7 depicts a flowchart illustrating a process for assembling abattery cell consistent with implementations of the current subjectmatter;

FIG. 8 depicts a flowchart illustrating a process for forming a negativethermal expansion fuse consistent with implementations of the currentsubject matter;

FIG. 9 depicts a table illustrating cell capacity at different dischargerates for a battery cell having a negative thermal expansion componentconsistent with implementations of the current subject matter;

FIG. 10 depicts a table illustrating battery cell temperature andbattery cell voltage measured during impact testing of a battery cellhaving a negative thermal expansion component consistent withimplementations of the current subject matter;

FIG. 11 depicts a table illustrating battery cell temperature andbattery cell voltage measured during overcharge testing of a batterycell having a negative thermal expansion component consistent withimplementations of the current subject matter;

FIG. 12 depicts a table illustrating cell capacity at differentdischarge rates for a reference battery cell without a negative thermalexpansion component consistent with implementations of the currentsubject matter;

FIG. 13 depicts a table illustrating battery cell temperature andbattery cell voltage measured during overcharge testing of a referencebattery cell without a negative thermal expansion component consistentwith implementations of the current subject matter; and

FIG. 14 depicts a table illustrating examples of negative temperatureexpansion materials consistent with implementations of the currentsubject matter.

When practical, similar reference numbers denote similar structures,features, or elements.

DETAILED DESCRIPTION

An electric power system can overcharge, overheat, and/or short circuitduring operation. For example, overcurrent can occur in an energystorage system such as, for example, a battery cell, when the batterycell is overcharged and/or develops an internal short circuit. Thebattery cell can develop an internal short circuit as the result ofcompressive shocks to the battery cell and/or the growth of dendritesthat form a low impedance path between the electrodes of the batterycell. Meanwhile, the battery cell can become overcharged when excesscurrent is applied to battery cell, for example, when the battery cellis in a fully charged state. Both the internal short circuit andovercharging can cause irreversible damage to the battery cell.Furthermore, the internal short circuit and overcharging can lead tothermal runaway, a hazardous condition in which undissipated heat fromthe overheating battery cell accelerates exothermic reactions within thebattery cell to further increase the temperature of the battery. Theconsequences of thermal runaway can be especially dire including, forexample, fire, explosions, and/or the like. As such, in someimplementations of the current subject matter, an electric power systemcan be coupled with a negative thermal expansion component foreliminating the hazards associated with the electric power systemoverheating, overcharging, and/or short circuiting.

In some implementations of the current subject matter, the negativethermal expansion component can be formed from a material havingnegative thermal expansion properties. For example, the negative thermalexpansion component can contract when subject to a temperature increase.The contraction of the negative thermal expansion component can create anonconductive gap that interrupt the flow of current through theelectric power system. As such, the negative thermal expansion componentcan prevent the electric power system from being exposed to excesscurrent. In doing so, the negative thermal expansion component caneliminate the hazards associated with overcurrent including, forexample, fires, explosions, and/or damage to the electric power system.

In some implementations of the current subject matter, the negativethermal expansion component can be integrated into the electric powersystem which, as noted, can be a circuit, an electric appliance, anelectric generator, an energy storage system, and/or the like. Forexample, the negative thermal expansion component can include one ormore layers of negative thermal expansion material disposed between theelectrodes, the current collectors, and/or the separator of a batterycell. Alternatively and/or additionally, the negative thermal expansioncomponent can be implemented as a fuse, which can be deployed on aninterior and/or an exterior of the electric power system. As noted, thenegative thermal expansion component can contract upon exposure to atemperature increase. The contraction of the negative thermal expansioncomponent can form a nonconductive gap that interrupts a flow of currentthrough the electric power system.

As noted, the negative thermal expansion component can be formed from amaterial having negative thermal expansion properties. According to someimplementations of the current subject matter, the negative thermalexpansion component can be formed from one or more oxides exhibitingnegative thermal expansion properties. It should be appreciated thatoxides can withstand extremely high voltage, for example, in excess of10,000 volts, without undergoing structural degradation. As such, thenegative thermal expansion component can be deployed in high voltageapplications including, for example, electric vehicles, power grids,and/or the like.

In some implementations of the current subject matter, the negativethermal expansion component can be formed from a silicate (e.g.,LiAlSiO₄ (β-eucryptite), Li₂Al₂Si_(n+2n) (β-spodumenes), Mg₂Al₄Si₅O₁₈(cordierite), and/or the like), zirconium tungstate (e.g., ZrW₂O₈,ZrW₂O₇, and/or the like), cyanides (e.g., Cd(CN)₂, ReO₃, (HfMg)(WO₄)₃,and/or the like), ruthenate (Ca₂RuO₄ _(▪) _(y)), siliceous faujasite,Fe₃Pt, perovskite oxides (e.g., nickel-based perovskite oxideBi_(0.95)La_(0.05)NiO₃ and/or the like), antiperovskites (e.g., Ni₃AX,Ni₃MgC, Ni₃ZnN_(1-δ), and/or the like), zeolites, samarium fulleride(Sm_(2.75)C₆₀), LaCu₃Fe₄O₁₂, invar alloys (e.g., Fe—Ni—Co and/or thelike), metal oxides (e.g., AM₂O₈, AM₂O₇, A₂M₃O₁₂, and/or the like),low-dimensional materials (e.g., zero-dimensional fullerene andclusters, one-dimensional carbon nanotubes, and two-dimensional graphiteand/or graphene, and/or the like), metal fluorides (e.g., ScF₃ and/orthe like), mechanoresponsive polymers, porous polyacrylamide (PAAM),dibenzocyclooctadienes (DBCOD), a polyacrylamide film containingdibenzocyclooctadiene (DBCOD), and/or the like. Alternatively and/oradditionally, the negative thermal expansion component can be formedfrom a composite containing at least one negative thermal expansionmaterial including, for example, ZrW₂O₈/copper, ZrW₂O₈/aluminum,ZrW₂O₈/phenolic resin, ZrW₂O₈/polyimide, β-eucryptite/copper, and/or thelike.

For example, perovskite oxide (Bi_(0.95)La_(0.05)NiO₃) can exhibit anegative thermal expansion coefficient of −82 ppm K⁻¹ when subject totemperatures T_(oper) between 320 kelvins (K) and 380 kelvins (K). Anegative thermal expansion component formed from perovskite oxide(Bi_(0.95)La_(0.05)NiO₃) and having an original length of 1 millimetercan contract and form a 8.2 micrometer nonconductive gap upon beingsubject to a temperature increase of 100 kelvins (K). Alternativelyand/or additionally, dibenzocyclooctadienes (DBCOD) and/or apolyacrylamide film containing dibenzocyclooctadiene (DBCOD) can beassociated with a negative thermal expansion coefficient of −1200 ppmK⁻¹ at ambient and/or near ambient temperatures. Thus, a negativethermal expansion component formed from dibenzocyclooctadienes (DBCOD)and/or a polyacrylamide film containing dibenzocyclooctadiene (DBCOD)and having an original length of 1 millimeter can contract and form a120 micrometer nonconductive gap when subject to a temperature increaseof 100 kelvins (K). As noted, the formation of a nonconductive gap candisrupt current flow through an electric power system (e.g., a circuit,an electric appliance, an electric generator, an energy storage system,and/or the like), thereby prevent a thermal runaway when the electricpower system is exposed to a surge in voltage, current, and/ortemperature.

It should be appreciated that the nonconductive gap can also be formedby gas and/or liquids released by the current interrupter. Alternatelyand/or additionally, the nonconductive gap can be formed by thedecomposition of the current interrupter. Batteries that include currentinterrupters that release gas and/or liquids and/or decompose aredescribed in International Patent Publication No. WO 2016/086184, thedisclosure of which is incorporated herein by reference.

FIG. 1 depicts a schematic diagram illustrating an example of a batterycell 100 having a negative thermal expansion component consistent withimplementations of the current subject matter. As shown in FIG. 1, thebattery cell 100 can include an electrode 110 and a current collector120. The electrode 110 can be an anode and/or a cathode of the batterycell 100. Although not shown, the battery cell 100 can include anothercurrent collector and another electrode having an opposite polarity asthe electrode 110.

Referring again to FIG. 1, the battery cell 100 can include a negativethermal expansion component. For instance, in some implementations ofthe current subject matter, the negative thermal expansion component canbe a negative thermal expansion current interrupter 130 interposedbetween the electrode 110 and the current collector 120. As shown inFIG. 1, subjecting the battery cell 100 to heat can cause the negativethermal expansion current interrupter 130 to contract. For example, thetemperature of the battery cell 100 can increase when the battery cell100 overcharges, overheats, and/or develops an internal short circuit.The negative thermal expansion current interrupter 130 can respond tothe increase in temperature by contracting. For instance, the negativethermal expansion current interrupter 130 can contract isotropically oruniformly in all directions. Alternatively and/or additionally, thenegative thermal expansion current interrupter 130 can contractanisotropically or non-uniformly in different directions. It should beappreciated that the manner in which the negative thermal expansioncurrent interrupter 130 contracts (e.g., isotropically and/oranisotropically) can depend on a design (e.g., dimensions, shape, and/orthe like) of the negative thermal expansion current interrupter 130and/or the materials used to form the negative thermal expansion currentinterrupter 130.

In some implementations of the current subject matter, the contractionof the negative thermal expansion current interrupter 130 can form anonconductive gap between the electrode 110 and the current collector120. For example, the nonconductive gap can be formed when thecontracting negative thermal expansion current interrupter 130 at leastpartially detaches from the electrode 110 and/or the current collector120, thereby electrically decoupling the electrode 110 and the currentcollector 120. It should be appreciated that the nonconductive gap canbe full and/or a partial gap between the electrode 110 and the currentcollector 120. Furthermore, the nonconductive gap can also be formed bygas and/or liquids released by the negative thermal expansion currentinterrupter 130. Alternatively and/or additionally, the nonconductivegap can be formed due a decomposition of the negative thermal expansioncurrent interrupter 130. The presence of the nonconductive gap betweenthe electrode 110 and the current collector 120 can interrupt a flow ofcurrent through the battery cell 100, thereby neutralizing the risksassociated with overcurrent.

In some implementations of the current subject matter, the negativethermal expansion current interrupter 130 can be formed from a materialhaving negative thermal expansion properties including, for example, oneor more oxides. For example, the negative thermal expansion currentinterrupter 130 can be formed from a silicate (e.g., LiAlSiO₄(β-eucryptite), Li₂Al₂Si_(n)O_(4+2n) (β-spodumenes), Mg₂Al₄Si₅O₁₈(cordierite), and/or the like), zirconium tungstate (e.g., ZrW₂O₈,ZrW₂O₇, and/or the like), cyanides (e.g., Cd(CN)₂, ReO₃, (HfMg)(WO₄)₃,and/or the like), ruthenate (Ca₂RuO₄ _(▪) _(y)), siliceous faujasite,Fe₃Pt, perovskite oxides (e.g., nickel-based perovskite oxideBi_(0.95)La_(0.05)NiO₃ and/or the like), antiperovskites (e.g., Ni₃AX,Ni₃MgC, Ni₃ZnN_(1-δ), and/or the like), zeolites, samarium fulleride(Sm_(2.75)C₆₀), LaCu₃Fe₄O₁₂, invar alloys (e.g., Fe—Ni—Co and/or thelike), metal oxides (e.g., AM₂O₈, AM₂O₇, A₂M₃O₁₂, and/or the like),low-dimensional materials (e.g., zero-dimensional fullerene andclusters, one-dimensional carbon nanotubes, and two-dimensional graphiteand/or graphene, and/or the like), metal fluorides (e.g., ScF₃ and/orthe like), mechanoresponsive polymers, porous polyacrylamide (PAAM),dibenzocyclooctadienes (DBCOD), a polyacrylamide film containingdibenzocyclooctadiene (DBCOD), and/or the like. Alternatively and/oradditionally, the negative thermal expansion current interrupter 130 canbe formed from a composite containing at least one negative thermalexpansion material including, for example, ZrW₂O₈/copper,ZrW₂O₈/aluminum, ZrW₂O₈/phenolic resin, ZrW₂O₈/polyimide,β-eucryptite/copper, and/or the like. Other examples of materialsexhibiting negative thermal expansion properties are shown in FIG. 15,which depicts a table 1500 illustrating examples of negative thermalexpansion materials consistent with implementations of the currentsubject matter.

In some implementations of the current subject matter, the battery cell100 can be a lithium (Li) ion battery. The negative thermal expansioncurrent interrupter 130 can be formed by coating a mixture of 90% ScF₃,5% carbon black, and 5% polyvinylidene fluoride (PVDF) onto aluminum(Al) foil with a loading of 2 milligrams per square centimeter (mg/cm²).The electrode 110 can be a lithium (e.g., LiCoO₂) cathode of the batterycell 110, which can be formed by coating a mixture of 5% plasma chemicalvapor deposition (PCVD) and 5% carbon additive atop a ScF₃ surface.Alternatively and/or additionally, the electrode 110 can be a graphite(C) anode of the battery cell 100.

FIG. 2 depicts a schematic diagram illustrating an example of thebattery cell 100 having a negative thermal expansion componentconsistent with implementations of the current subject matter. As shownin FIG. 2, the battery cell 100 can further include a separator 140interposed between the two electrodes of the battery cell 100 including,for example, the electrode 110 and another electrode having an oppositepolarity as the electrode 110. The electrode 110 can be an anode and/ora cathode of the battery cell 100. Although not shown in FIG. 2, thebattery cell 100 can include another electrode as well as a currentcollector coupled with of the two electrodes.

As noted, the battery cell 100 can include the negative thermalexpansion current interrupter 130. In some implementations of thecurrent subject matter, the negative thermal expansion currentinterrupter 130 can be interposed between the electrode 110 and theseparator 140 instead of and/or in addition to being interposed betweenthe electrode 110 and the current collector 120. As shown in FIG. 2,subjecting the battery cell 100 to heat can cause the negative thermalexpansion current interrupter 130 to contract. For example, thetemperature of the battery cell 100 can increase when the battery cell100 overcharges, overheats, and/or develops an internal short circuit.The negative thermal expansion current interrupter 130 can respond tothe increase in temperature by contracting isotropically and/oranisotropically. For instance, the manner in which the negative thermalexpansion current interrupter 130 contracts (e.g., isotropically and/oranisotropically) can depend on a design (e.g., dimensions, shape, and/orthe like) of the negative thermal expansion current interrupter 130and/or the materials used to form the negative thermal expansion currentinterrupter 130.

In some implementations of the current subject matter, the contractionof the negative thermal expansion current interrupter 130 can form anonconductive gap between the electrode 110 and the separator 140. Forexample, the nonconductive gap can be formed when the contractingnegative thermal expansion current interrupter 130 at least partiallydetaches from the electrode 110 and/or the separator 140, therebyelectrically decoupling the electrode 110 and the separator 140. Itshould be appreciated that the nonconductive gap can be a partial and/ora full gap between the electrode 110 and the separator 140. Furthermore,the nonconductive gap can also be formed by gas and/or liquids releasedby the negative thermal expansion current interrupter 130. Alternativelyand/or additionally, the nonconductive gap can be formed due adecomposition of the negative thermal expansion current interrupter 130.The presence of the nonconductive gap between the electrode 110 and theseparator 140 can interrupt a flow of current through the battery cell100, thereby neutralizing the risks associated with overcurrent.

In some implementations of the current subject matter, the negativethermal expansion current interrupter 130 can be formed from a materialhaving negative thermal expansion properties including, for example, oneor more oxides. For example, the negative thermal expansion currentinterrupter 130 can be formed from a silicate (e.g., LiAlSiO₄(β-eucryptite), Li₂Al₂Si_(n)O_(4+2n) (β-spodumenes), Mg₂Al₄Si₅O₁₈(cordierite), and/or the like), zirconium tungstate (e.g., ZrW₂O₈,ZrW₂O₇, and/or the like), cyanides (e.g., Cd(CN)₂, ReO₃, (HfMg)(WO₄)₃,and/or the like), ruthenate (Ca₂RuO₄ _(▪) _(y)), siliceous faujasite,Fe₃Pt, perovskite oxides (e.g., nickel-based perovskite oxideBi_(0.95)La_(0.05)NiO₃ and/or the like), antiperovskites (e.g., Ni₃AX,Ni₃MgC, Ni₃ZnN_(1-δ), and/or the like), zeolites, samarium fulleride(Sm_(2.75)C₆₀), LaCu₃Fe₄O₁₂, invar alloys (e.g., Fe—Ni—Co and/or thelike), metal oxides (e.g., AM₂O₈, AM₂O₇, A₂M₃O₁₂, and/or the like),low-dimensional materials (e.g., zero-dimensional fullerene andclusters, one-dimensional carbon nanotubes, and two-dimensional graphiteand/or graphene, and/or the like), metal fluorides (e.g., ScF₃ and/orthe like), mechanoresponsive polymers, porous polyacrylamide (PAAM),dibenzocyclooctadienes (DBCOD), a polyacrylamide film containingdibenzocyclooctadiene (DBCOD), and/or the like. Alternatively and/oradditionally, the negative thermal expansion current interrupter 130 canbe formed from a composite containing at least one negative thermalexpansion material including, for example, ZrW₂O₈/copper,ZrW₂O₈/aluminum, ZrW₂O₈/phenolic resin, ZrW₂O₈/polyimide,β-eucryptite/copper, and/or the like. As noted, other examples ofmaterials exhibiting negative thermal expansion properties are depictedin the table 1500 of FIG. 15.

FIG. 3 depicts a schematic diagram illustrating an example of thebattery cell 100 having a negative thermal expansion componentconsistent with implementations of the current subject matter. As shownin FIG. 3, the battery cell 100 can further include another electrode150 having an opposite polarity as the electrode 110. Furthermore, insome implementations of the current subject matter, the negative thermalexpansion component can include multiple negative thermal expansioncurrent interrupters including, for example, the negative thermalexpansion current interrupter 130 and another negative thermal expansioncurrent interrupter 160. Although not shown, it should be appreciatedthat the battery cell 100 can include a separator interposed between theelectrode 110 and the other electrode 150.

In some implementations of the current subject matter, the negativethermal expansion current interrupter 130 can be interposed between theelectrode 110 and the current collector 120. Meanwhile, the othernegative thermal expansion current interrupter 160 can be interposedbetween the two electrodes of the battery cell 100 including, forexample, the electrode 110 and the other electrode 150. As shown in FIG.3, subjecting the battery cell 100 to heat can cause the negativethermal expansion current interrupter 130 and/or the other negativethermal expansion current interrupter 160 to contract. For example, thetemperature of the battery cell 100 can increase when the battery cell100 overcharges, overheats, and/or develops an internal short circuit.The negative thermal expansion current interrupter 130 and/or the othernegative thermal expansion current interrupter 160 can respond to theincrease in temperature by contracting isotropically and/oranisotropically. It should be appreciated that the manner in which thenegative thermal expansion current interrupter 130 and/or the othernegative thermal expansion current interrupter 160 contract (e.g.,isotropically and/or anisotropically) can depend on a design (e.g.,dimensions, shape, and/or the like) and/or the materials forming the thenegative thermal expansion current interrupter 130 and/or the othernegative thermal expansion current interrupter 160.

In some implementations of the current subject matter, the contractionof the negative thermal expansion current interrupter 160 can form anonconductive gap between the electrode 110 and the other electrode 150.Alternatively and/or additionally, the other negative thermal expansioncurrent interrupter 130 can also contract to form an additionalnonconductive gap between the electrode 110 and the current collector120. These nonconductive gaps can also be formed by gas and/or liquidsreleased by the negative thermal expansion current interrupter 130.Alternatively and/or additionally, the nonconductive gaps can be formeddue a decomposition of the negative thermal expansion currentinterrupter 130. The presence of the nonconductive gaps can interrupt aflow of current through the battery cell 100, thereby neutralizing therisks that arise when the battery cell 100 overcharges, overheats,and/or develops an internal short circuit.

In some implementations of the current subject matter, the negativethermal expansion current interrupter 130 and/or the other negativethermal expansion current interrupter 160 can be formed from a materialhaving negative thermal expansion properties including, for example, oneor more oxides. For example, the negative thermal expansion currentinterrupter 130 can be formed from a silicate (e.g., LiAlSiO₄(β-eucryptite), Li₂Al₂Si_(n)O_(4+2n) (β-spodumenes), Mg₂Al₄Si₅O₁₈(cordierite), and/or the like), zirconium tungstate (e.g., ZrW₂O₈,ZrW₂O₇, and/or the like), cyanides (e.g., Cd(CN)₂, ReO₃, (HfMg)(WO₄)₃,and/or the like), ruthenate (Ca₂RuO₄ _(▪) _(y)), siliceous faujasite,Fe₃Pt, perovskite oxides (e.g., nickel-based perovskite oxideBi_(0.95)La_(0.05)NiO₃ and/or the like), antiperovskites (e.g., Ni₃AX,Ni₃MgC, Ni₃ZnN_(1-δ), and/or the like), zeolites, samarium fulleride(Sm_(2.75)C₆₀), LaCu₃Fe₄O₁₂, invar alloys (e.g., Fe—Ni—Co and/or thelike), metal oxides (e.g., AM₂O₈, AM₂O₇, A₂M₃O₁₂, and/or the like),low-dimensional materials (e.g., zero-dimensional fullerene andclusters, one-dimensional carbon nanotubes, and two-dimensional graphiteand/or graphene, and/or the like), metal fluorides (e.g., ScF₃ and/orthe like), mechanoresponsive polymers, porous polyacrylamide (PAAM),dibenzocyclooctadienes (DBCOD), a polyacrylamide film containingdibenzocyclooctadiene (DBCOD), and/or the like. Alternatively and/oradditionally, the negative thermal expansion current interrupter 130and/or the other negative thermal expansion current interrupter 160 canbe formed from a composite containing at least one negative thermalexpansion material including, for example, ZrW₂O₈/copper,ZrW₂O₈/aluminum, ZrW₂O₈/phenolic resin, ZrW₂O₈/polyimide,β-eucryptite/copper, and/or the like. As noted, other examples ofmaterials exhibiting negative thermal expansion properties are depictedin table 1500 of FIG. 15.

FIGS. 1-3 depicts a negative thermal expansion component that isintegrated into an electric power system such as, for example, a batterycell, a battery pack, and/or the like. However, as noted, in someimplementations of the current subject matter, a negative thermalexpansion component can also be implemented as a fuse, which can becoupled to an exterior and/or an interior of an electric power system.To further illustrate, FIG. 4A depicts a schematic diagram illustratinga negative thermal expansion fuse 400 coupled with an electric powersystem 450 consistent with implementations of the current subjectmatter. As shown in FIG. 4A, the negative thermal expansion fuse 400 canbe coupled to a positive terminal of the electric power system 450.However, it should be appreciated that the negative thermal expansionfuse 400 can also be coupled to a negative terminal of the electricpower system 450. Furthermore, the electric power system 450 can be anytype of electric power system including, for example, a circuit, anelectric appliance, an electric generator, an energy storage system,and/or the like. For example, the electric power system 450 can be abattery, a converter (e.g., a DC/DC voltage converter, an AC/DCconverter, a DC/AC converter, and/or the like), and/or the like. Thenegative thermal expansion fuse 400 can be installed between an electricgenerator (e.g., solar cell, solar panel, and/or the like) and an energystorage system containing rechargeable batteries, supercapacitors, flowbatteries, fuel cells, and/or the like.

FIG. 4B depicts a cross sectional view of an example of the negativethermal expansion fuse 400 consistent with implementations of thecurrent subject matter. Meanwhile, FIG. 4C depicts an exploded view ofan example of the negative thermal expansion fuse 400 consistent withimplementations of the current subject matter. Referring to FIGS. 4A-C,the negative thermal expansion fuse 400 can include a first metal plate410A and a second metal plate 410B. Furthermore, the negative thermalexpansion fuse 400 can include a negative thermal expansion plate 420interposed between the first metal plate 410A and the second metal plate410B. Although FIG. 4C depicts the negative thermal expansion fuse 400as having an annular and/or disk configuration, it should be appreciatedthat the negative thermal expansion fuse 400 can have a different shapeand/or configuration than shown including, for example, triangular,rectangular, and/or the like.

In some implementations of the current subject matter, the first metalplate 410A and/or the second metal plate 410B can be formed from a metalsuch as, for example, nickel (Ni) and/or the like. Meanwhile, thenegative thermal expansion plate 420 can be a hybrid negative thermalexpansion component that includes a negative thermal expansion portion422 and a nonconductive portion 424. According to some implementationsof the current subject matter, the nonconductive portion 424 can beconfigured to provide structural support. Alternatively and/oradditionally, the nonconductive portion 424 can be formed from anynon-conducting material and/or non-conducting composite including, forexample, non-conducting oxides (e.g., aluminum oxide, iron oxide, and/orthe like), non-conducting ceramics (e.g., silicon oxide, boron glass,and/or the like), a non-conducting polymer (e.g., poly ethylene,polyvinylidine fluoride (PVDF), and/or the like), materials having apositive thermal coefficient (PTC), and/or the like. Where thenonconductive portion 424 of the negative thermal expansion plate 420 isformed from a positive temperature coefficient (PTC) material, thenonconductive portion 424 can undergo a phase transition when subject totemperature exceeding a threshold value.

The negative thermal expansion portion 422 can be formed from anymaterial having negative thermal expansion properties including, forexample, silicate (e.g., LiAlSiO₄ (β-eucryptite), Li₂Al₂Si_(n)O_(4+2n)(β-spodumenes), Mg₂Al₄Si₅O₁₈ (cordierite), and/or the like), zirconiumtungstate (e.g., ZrW₂O₈, ZrW₂O₇, and/or the like), cyanides (e.g.,Cd(CN)₂, ReO₃, (HfMg)(WO₄)₃, and/or the like), ruthenate (Ca₂RuO₄ _(▪)_(y)), siliceous faujasite, Fe₃Pt, perovskite oxides (e.g., nickel-basedperovskite oxide Bi_(0.95)La_(0.05)NiO₃ and/or the like),antiperovskites (e.g., Ni₃AX, Ni₃MgC, Ni₃ZnN_(1-δ), and/or the like),zeolites, samarium fulleride (Sm_(2.75)C₆₀), LaCu₃Fe₄O₁₂, invar alloys(e.g., Fe—Ni—Co and/or the like), metal oxides (e.g., AM₂O₈, AM₂O₇,A₂M₃O₁₂, and/or the like), low-dimensional materials (e.g.,zero-dimensional fullerene and clusters, one-dimensional carbonnanotubes, and two-dimensional graphite and/or graphene, and/or thelike), metal fluorides (e.g., ScF₃ and/or the like), mechanoresponsivepolymers, porous polyacrylamide (PAAM), dibenzocyclooctadienes (DBCOD),a polyacrylamide film containing dibenzocyclooctadiene (DBCOD), and/orthe like. Alternatively and/or additionally, the negative thermalexpansion plate 420 can be formed from a composite containing at leastone negative thermal expansion material including, for example,ZrW₂O₈/copper, ZrW₂O₈/aluminum, ZrW₂O₈/phenolic resin, ZrW₂O₈/polyimide,β-eucryptite/copper, and/or the like. As noted, table 1500 shown in FIG.15 illustrates other examples of negative thermal expansion materialsconsistent with implementations of the current subject matter.

Referring again to FIG. 4B, the negative thermal expansion portion 422of the negative thermal expansion plate 420 can contract when thenegative thermal expansion fuse 400 is subject to heat. Alternativelyand/or additionally, when the nonconductive portion 424 includes apositive temperature coefficient (PTC) material, the nonconductiveportion 424 can undergo a phase transition when subject to temperatureexceeding a threshold value. It should be appreciated that thenonconductive portion 424 can be formed from any positive temperaturecoefficient (PTC) material including, for example, poly ethylene,polyvinylidene fluoride (PVDF), acrylonitrile butadiene styrene (ABS)thermoplastic, glass and/or fiber-reinforced acrylonitrile butadienestyrene (ABS), acetal, amber, benzocyclobutene, cellulose acetate (CA),cellulose acetate butynate (CAB), cellulose nitrate (CN), chlorinatedpolyether, chlorinated polyvinylchloride (CPVC), ethylene ethyl acrylate(EEA), ethylene vinyl acetate (EVA), fluoroethylene propylene (FEP),fluorspar, CaF₂, gutta percha, nylon molding and/or extruding compound,paraffin, polybutylene (PB), polyamide (PA), polyester, polypropylene(PP), and/or the like.

The negative thermal expansion fuse 400 can be exposed to increasedtemperatures due to excess heat generated by a larger than intendedcurrent flows through the electric power system 450. In someimplementations of the current subject matter, the negative thermalexpansion portion 422 of the negative thermal expansion plate 420 cancontinue to contract as the temperature continues to increase.Meanwhile, the nonconductive portion 424 of the negative thermalexpansion plate 420 can undergo a phase transition once the temperaturereaches a threshold value. It should be appreciated that this phasetransition can include a solid to liquid phase transition, a solid togas phase transition, a liquid to gas transition, and/or the like. Thenonconductive portion 424 can expand as a result of undergoing the phasetransition.

The contraction of the negative thermal expansion portion 422 of thenegative thermal expansion plate 420 can cause the negative thermalexpansion plate 420 to at least partially detach from the first metalplate 410A and/or the second metal plate 410B, thereby creating anonconductive gap between the first metal plate 410A and the secondmetal plate 410B. Alternatively and/or additionally, the expansion ofthe nonconductive portion 424 of the negative thermal expansion plate420 can enlarge the nonconductive gap by further separating the negativethermal expansion plate 420 from the first metal plate 410A and/or thesecond metal plate 410B. The conductive gap between the first metalplate 410A and the second metal plate 410B can be a partial and/or afull gap. In some implementations of the current subject matter, thisnonconductive gap between the first metal plate 410A and the secondmetal plate 410B can serve as a circuit breaker interrupting the flow ofcurrent through the electric power system 450. As such, the negativethermal expansion fuse 400 can eliminate the hazards that arise when theelectric power system 450 is overheated, overcharged, and/or develops ashort circuit.

FIG. 5 depicts a schematic diagram illustrating another example of ahybrid negative thermal expansion component 500 consistent withimplementations of the current subject matter. Referring to FIGS. 1-3and 4A-C, the hybrid negative thermal expansion component 500 canimplement the negative thermal expansion current interrupter 130, thenegative thermal expansion current interrupter 160, and/or the negativethermal expansion plate 420.

In some implementations of the current subject matter, the hybridnegative thermal expansion component 500 can include a phase transitionlayer 510 formed from a material that undergoes a phase transition whenexposed to temperatures in excess of a threshold value. For example,when the phase transition layer 510 is exposed to temperatures in excessof the threshold value, the phase transition layer 510 can undergo asolid to liquid phase transition, a solid to gas phase transition, aliquid to gas transition, and/or the like. The phase transition cancause the phase transition layer 510 to expand in response totemperatures in excess of the threshold value. It should be appreciatedthat the phase transition layer 510 can be formed from any material thatresponds to being exposed to temperatures in excess of the thresholdvalue by undergoing a phase transition. For instance, the phasetransition layer 510 can be formed from a positive temperaturecoefficient (PTC) material such as, for example, poly ethylene,polyvinylidene fluoride (PVDF), acrylonitrile butadiene styrene (ABS)thermoplastic, glass and/or fiber-reinforced acrylonitrile butadienestyrene (ABS), acetal, amber, benzocyclobutene, cellulose acetate (CA),cellulose acetate butynate (CAB), cellulose nitrate (CN), chlorinatedpolyether, chlorinated polyvinylchloride (CPVC), ethylene ethyl acrylate(EEA), ethylene vinyl acetate (EVA), fluoroethylene propylene (FEP),fluorspar, CaF₂, gutta percha, nylon molding and/or extruding compound,paraffin, polybutylene (PB), polyamide (PA), polyester, polypropylene(PP), and/or the like.

In some implementations of the current subject matter, the phasetransition layer 510 can be coupled with a negative thermal expansionlayer 520. The negative thermal expansion layer 520 can be formed from amaterial having negative thermal expansion properties. As such, thenegative thermal expansion layer 520 can contract when exposed toincreasing temperatures. Furthermore, the contraction of the negativethermal expansion layer 520 can be continuous. That is, the negativethermal expansion layer 250 can continue to contract as the temperaturecontinues to increase. By contrast, it should be appreciated that thephase transition layer 510 can undergo a single discrete phasetransition at the threshold temperature.

In some implementations of the current subject matter, the negativethermal expansion layer 520 can be interposed between the phasetransition layer 510 and another phase transition layer 530. However, itshould be appreciated that the phase transition layer 530 is optional.Alternatively and/or additionally, the hybrid negative thermal expansioncomponent 500 can include multiple layers of phase transition materialand negative thermal expansion material. According to someimplementations of the current subject matter, the negative thermalexpansion layer 520 can contract in response to increasing temperatureswhereas the phase transition layer 510 and/or the phase transition layer530 can expand when the temperature exceeds a threshold value. Thecontraction of the negative thermal expansion layer 520 can form anonconductive gap, which can be further enlarged by the expansion of thephase transition layer 510 and/or the phase transition layer 530.

FIG. 6 depicts as flowchart illustrating a process 600 for preparing anelectrode layered with a negative thermal expansion material consistentwith implementations of the current subject matter. Referring to FIGS.1-3 and 6, the process 600 can be performed to form the negative thermalexpansion current interrupter 130 on top of the electrode 110.

The negative thermal expansion current interrupter 130 can be formed(602). For example, the negative thermal expansion current interrupter130 can be formed by dissolving a binder into a solvent. A conductiveadditive and a negative thermal expansion material can be added to thebinder solution to form a slurry. The slurry can be coated onto asurface of a metal foil. Drying the slurry can result in the formationof the negative thermal expansion current interrupter 130 on the surfaceof the metal foil.

The electrode 110 can be formed on top of the negative thermal expansioncurrent interrupter 130 (604). For example, the electrode 110 can beformed by dissolving a binder into a solvent. A conductive additive canbe added to the binder solution to form a slurry. Furthermore, activeelectrode material can be added to the slurry before the slurry iscoated onto the negative thermal expansion current interrupter 130formed in operation 602 and compressed into a desired thickness.

FIG. 7 depicts a flowchart illustrating a process 700 for assembling abattery cell consistent with implementations of the current subjectmatter. Referring to FIGS. 1-3 and 6-7, the process 600 can be performedto form the battery cell 100.

The electrodes of the battery cell can be formed by punching sheets ofelectrode material into appropriately shaped and/or sized pieces (702).For instance, sheets of cathode material and/or anode material can bepunched into appropriately shaped and/or sized pieces using an electrodetab. The resulting electrodes can be dried (704). For example, thecathode of the battery cell can be dried at 125° C. for 10 hours whilethe anode of the battery cell can be dried at 140° C. for 10 hours.

A layer of separator can be laminated between the electrodes of thebattery cell to form a flat jelly-roll (706). The flat jelly-roll can beplaced in a composite bag (708). For instance, the flat jelly-rollformed in operation 706 can be placed inside an aluminum (Al) compositebag. The flat jelly-roll can be dried inside the composite bag (710).For example, the flat jelly-roll inside the aluminum (Al) composite bagcan be dried at 70° C. for 10 hours. The composite bag can be filledwith electrolyte and sealed to complete the assembly of the battery cell(712).

The assembled battery cell can be aged (714). For instance, the batterycell formed in operation 712 can be aged for 36 hours. The assembled andaged battery cell can be activated by subjecting the battery cell to aformation process (716). For example, the battery cell can undergo aformation process, which refers to a controlled charge and dischargecycle configured to activate the chemical components of the batterycell. This formation process can require the battery cell to be chargedby being exposed to a gradually increasing current instead of a constantcurrent such that the buildup of voltage within the battery cell isgradual. It should be appreciated that the battery cell can be ready forgrading and/or use subsequent to the completion of the formationprocess.

In some implementations of the current subject matter, a battery cellhaving a negative thermal expansion component such as, for example, thebattery cell 100 with the negative thermal expansion current interrupter130 can be immune to the deleterious effects of overcharging,overheating, and/or internal short circuits. The negative thermalexpansion component can contract in response to an increase intemperature, thereby forming one or more nonconductive gaps thatinterrupt the current flowing through the battery cell. As FIGS. 9 and12 show, a battery cell having a negative thermal expansion componentcan have comparable capacity as a battery without a negative thermalexpansion component. However, as shown in FIG. 10, including thenegative thermal expansion component in the battery cell can prevent thebattery cell from catching fire and/or exploding when subject to impact.For example, FIG. 10 shows that subjecting the battery cell to impact(e.g., from a 9.1 kilogram steel rod) can cause the voltage of thebattery cell to decrease to approximately zero volts and the temperatureof the battery cell to increase to approximately 100° C. Nevertheless,the battery cell, due to the presence of the negative thermal expansioncomponent, did not catch fire and/or explode as a result of the impact.

Furthermore, as FIG. 11 shows, the battery cell having the negativethermal expansion component can withstand being overcharged withoutcatching fire and/or exploding. For instance, FIG. 11 shows the voltageand the temperature of the overcharging battery cell spiking beforetapering down and stabilizing after approximately 20 minutes, whichindicates a rapid increase in the impedance within the battery cell atapproximately the 20-minute mark. Contrastingly, FIG. 13 shows thetemperature of an overcharging reference cell without a negative thermalexpansion component gradually increasing until spiking to over 400° C.at the 48-minute mark, at which point the reference battery cell entersthermal runaway. FIG. 13 further shows the voltage of the referencebattery cell as being relatively stable before spiking when thereference battery cell enters thermal runaway. Unlike the battery cellwith the negative thermal expansion component, the impedance of thereference battery cell did not increase to thwart the reference batterycell from entering thermal runaway.

For example, a battery cell's response to impact can be tested bycharging the battery cell to 4.2 volts (V) with a 1-ampere current for 3hours. The fully charged battery cell can be placed on a hard surface.Furthermore, a thermal couple can be attached to a surface of thebattery cell while a voltage meter can be coupled to the positiveterminal and the negative terminal of the battery cell. A steel rodemeasuring 15.8 millimeters in diameter and 70 millimeters in length canbe positioned across the center of the batter cell. The battery cell canthen be subject to impact from a 9.1 kilogram (kg) steel block that issuspended at and released from a height of 610 millimeters above thebattery cell. The battery cell's voltage and temperature can be recordedafter the steel block is released for a free fall onto the steel barpositioned across the battery cell. A containment tube having aninterior diameter of 8 centimeters (cm) can be used to guide the steelblock in its free fall.

Example Battery Cell with Zirconium Tungstate Negative Thermal ExpansionComponent

In some implementations of the current subject matter, a battery cellcan include a negative thermal expansion component such as, for example,a negative thermal expansion current interrupter, formed from azirconium tungstate (e.g., ZrW₂O₈, ZrW₂O₇, and/or the like).Furthermore, the battery cell can include a lithium (Li) nickel cobaltmanganese (NMC) oxide cathode and an anode formed from mesocarbonmicrobeads (MCMB). According to some implementations of the currentsubject matter, the process 600 can be performed in order to prepare anelectrode layered with zirconium tungstate as the negative thermalexpansion material while the process 700 can be performed to order toassembly the battery cell.

In some implementations of the current subject matter, the negativethermal expansion component of the battery cell can be formed bydissolving 0.5 grams of Torlon®4000TF (0.5 g) into 4.5 grams ofN-methylpyrrolidone (NMP). Meanwhile, 3 grams of polyvinylidene fluoride(PVDF) can be dissolved into 34.5 grams of N-methylpyrrolidone (NMP).The Torlon®4000TF solution and the polyvinylidene fluoride (PVDF)solution can be combined with 0.2 grams of carbon black and mixed for 10minutes at a rate of approximate 6500 revolutions per minute. Thismixture is then combined with 21.3 grams of nano zirconium tungstatepowder (e.g., ZrW₂O₈, ZrW₂O₇, and/or the like) and mixed for 20 min atthe rate of approximately 6500 revolutions per minute. The resultingslurry can be coated onto one side of a 15 millimeter thick aluminum(Al) foil using an automatic coating machine with the first heat zoneset to approximately 130° C. and the second heat zone set toapproximately 160° C. Once the N-methylpyrrolidone (NMP) has evaporated,the final dried solid can have a loading of approximately 0.7 milligramsper square centimeter (mg/cm²).

In some implementations of the current subject matter, the cathode ofthe battery cell can be formed by dissolving 6 grams of polyvinylidenefluoride (PVDF) into 75 grams of N-methylpyrrolidone (NMP). Theresulting mixture can be combined with 6 grams of carbon black and mixedfor 15 minutes at a rate of approximately 6500 revolutions per minute(rpm). Here, 188 grams of nickel, manganese, and cobalt (NMC) can beadded to the mixture and mixed for 30 minutes at a rate of approximately6500 revolutions per minute (rmp). Some additional N-methylpyrrolidone(NMP) may be added to adjust the viscosity of the mixture. The resultingslurry can be coated onto the surface of the negative thermal expansioncomponent using an automatic coating machine with the first heat zoneset to about 85° C. and the second heat zone to about 135° C. Uponevaporating the N-methylpyrrolidone (NMP), the final dried solid canhave a loading (single side) of approximately 19.4 milligrams per squarecentimeter (mg/cm²). Furthermore, the final dried solid can becompressed to a thickness of approximately 119 microns (μm).

In some implementations of the current subject matter, the anode of thebattery cell can be formed by dissolving 14 grams of carboxymethylcellulose (CMC) into approximately 1077 grams of deionized water. Themixture can then be combined with 20 grams of carbon black and 8 gram ofgraphene before being mixed for 15 minutes at a rate of approximately6500 revolutions per minute (rpm). Here, the mixture can be furthercombined with 744.2 grams of mesocarbon microbeads (MCMB) and 140 gramsof synthetic graphite (TIMCAL) and mixed for 30 minutes at a rate ofapproximately 6500 revolutions per minute (rpm). In addition, 22 gramsof styrene butadiene rubber (SBR) with a 50% solid content suspended inwater and 3 grams of lithium neutralized polyimide can be added to themixture and mixed for 5 minutes at approximately 6500 revolutions perminute (rpm). The viscosity of the resulting slurry can be adjustedbefore the slurry is coated onto a 9 millimeter thick copper (Cu) foilusing an automatic coating machine with the first heat zone set to about100° C. and the second heat zone to about 130° C. Once the water hasbeen evaporated from the slurry coated atop the copper (Cu) foil, thefinal dried solid can have a loading of approximately 11.2 milligramsper square centimeter (mg/cm²). Furthermore, the final dried solid canbe compressed to a thickness of approximately 170 microns (μm).

In some implementations of the current subject matter, the battery cellcan be assembled by forming the cathode and anode of the battery cell,for example, by punching sheets of the lithium (Li) nickel cobaltmanganese (NMC) oxide cathode material and the mesocarbon microbead(MCMB) anode material into the appropriate shape and/or size using anelectrode tab. The cathode can be dried at 125° C. for 10 hours whilethe anode can be dried at 140° C. for 10 hours. A separator cansubsequently be laminated between the cathode and anode to form a flatjelly-roll. The flat jelly-roll can be placed into an aluminum (Al)composite bag and dried in a 70° C. vacuum oven. Thereafter, thealuminum (Al) composite bag can be filled with an organic carbonatebased electrolyte containing lithium hexafluorophosphate (LiPF₆),sealed, and aged for 16 hours. The assembled and aged battery cell canbe subject to a formation process that includes a charge and dischargecycle. For example, the battery cell can be charged to 4.2 volts firstat a C-rate of 0.02 C rate for 8 hours and then at a C-rate of 0.5 Crate for 2 hours. The charged battery cell can be rested for 20 minutesbefore being discharged to 2.8 volts at a C-rate of 0.5 C.

In some implementations of the current subject matter, upon completingthe formation process, the battery cell can be punctured to release anygases that accumulated during the assembly process and resealed. Thebattery cell can then be ready for use and/or grading including, forexample, impact testing, overcharge testing, discharge capacity testing,and/or the like.

Reference Battery Cell

A reference battery cell can be formed to serve as a control sampleproviding baseline performance statistics. The reference battery cellcan be formed without a negative thermal expansion component and cantherefore lack overcurrent protection. Furthermore, the referencebattery cell can include a lithium (Li) nickel cobalt manganese (NMC)oxide cathode and a mesocarbon microbead (MCMB) anode.

In some implementations of the current subject matter, the cathode ofthe reference battery cell can be formed by dissolving 21 grams ofpolyvinylidene fluoride (PVDF) into 262.5 grams of N-methylpyrrolidone(NMP). Furthermore, 8.4 grams of carbon black can be added to thesolution and mixed for 15 minutes at a rate of approximately 6500revolutions per minute (rpm). The mixture can be combined with 570.6grams of nickel, manganese, and cobalt (NMC) and mixed for 30 minutes ata rate of approximately 6500 revolutions per minute to form a flowableslurry. Additional N-methylpyrrolidone (NMP) can be added to the slurryto adjust the viscosity of the slurry before the slurry is coated onto15 millimeter (mm) thick aluminum (Al) foil using an automatic coatingmachine. The first heat zone of the automatic coating machine can be setto approximately 80° C. and the second heat zone of the automaticcoating machine can be set to approximately 130° C. to evaporate theN-methylpyrrolidone (NMP) from the slurry coated onto the aluminum (Al)foil. The resulting dried solid, which can have a loading ofapproximately 16.68 milligrams per square centimeter (mg/cm²), can becompressed to a thickness of approximately 124 microns (μm).

In some implementations of the current subject matter, the anode of thereference battery cell can be formed by dissolving 13 grams ofcarboxymethyl cellulose (CMC) into approximately 764 grams of deionizedwater. The mixture can then be combined with 20 grams of carbon blackand mixed for 15 minutes at a rate of approximately 6500 revolutions perminute (rpm). Here, the mixture can be further combined with 757.28grams of mesocarbon microbeads (MCMB) and 188.72 grams of syntheticgraphite (TIMCAL) and mixed for 30 minutes at a rate of approximately6500 revolutions per minute (rpm). In addition, 21 grams of styrenebutadiene rubber (SBR) with a 50% solid content suspended in water canbe added to the mixture and mixed for 5 minutes at approximately 6500revolutions per minute (rpm). The viscosity of the resulting slurry canbe adjusted before the slurry is coated onto a 9 millimeter thick copper(Cu) foil using an automatic coating machine with the first heat zoneset to about 95° C. and the second heat zone to about 125° C. Once thewater has been evaporated from the slurry coated atop the copper (Cu)foil, the final dried solid, which can have a loading of approximately11 milligrams per square centimeter (mg/cm²), can be compressed to athickness of approximately 149 microns (μm).

In some implementations of the current subject matter, the referencebattery cell can be assembled by forming the cathode and anode of thereference battery cell, for example, by punching sheets of the lithium(Li) nickel cobalt manganese (NMC) oxide cathode material and mesocarbonmicrobead (MCMB) anode material into the approximate shape and/or sizeusing an electrode tab. The cathode can be dried at 125° C. for 10 hourswhile the anode can be dried at 140° C. for 10 hours. A separator cansubsequently be laminated between the cathode and anode to form a flatjelly-roll. The flat jelly-roll can be placed into an aluminum (Al)composite bag and dried in a 70° C. vacuum oven. Thereafter, thealuminum (Al) composite bag can be filled with an organic carbonatebased electrolyte containing lithium hexafluorophosphate (LiPF₆),sealed, and aged for 16 hours. The assembled and aged battery cell canbe subject to a formation process that includes a charge and dischargecycle. For example, the reference battery cell can be charged to 4.2volts first at a C-rate of 0.02 C rate for 8 hours and then at a C-rateof 0.5 C rate for 2 hours. The charged battery cell can be rested for 20minutes before being discharged to 2.8 volts at a C-rate of 0.5 C.

In some implementations of the current subject matter, upon completingthe formation process, the reference battery cell can be punctured torelease any gases that accumulated during the assembly process andresealed. The reference battery cell can then be ready for use and/orgrading including, for example, impact testing, overcharge testing,discharge capacity testing, and/or the like.

FIG. 8 depicts a flowchart illustrating a process 800 for forming anegative thermal expansion fuse consistent with implementations of thecurrent subject matter. Referring to FIGS. 4A-C and 8, the process 800can be performed in order to form the negative thermal expansion fuse400 which, as noted, includes the negative thermal expansion plate 420interposed between the first metal plate 410A and the second metal plate410B.

The negative thermal expansion portion 422 of the negative thermalexpansion plate 420 can be formed (802). For example, the negativethermal expansion portion 422 can be formed by dissolving 0.05 grams ofpolyvinylidene fluoride (PVDF) into 6 grams of N-methylpyrrolidone(NMP). The solution can be combined with 5 grams of a negative thermalexpansion material and 1 gram of carbon black to form a paste.Furthermore, the paste can be dried at 100° C. for 24 hours. It shouldbe appreciated that the paste can be dried into any shape and/orconfiguration including, for example, annular, rectangular, and/or thelike.

The nonconductive portion 424 of the negative thermal expansion plate420 can be formed (804). For example, the nonconductive portion 424 canbe formed by mixing 5 grams of wax with 5 grams of polyvinylidenefluoride (PVDF). As noted, it should be appreciated that thenonconductive portion 424 can be formed to provide structural supportand/or exhibit positive temperature coefficient (PTC) properties.

The negative thermal expansion portion 422 and the nonconductive portion424 can be compressed to form the negative thermal expansion plate 420(806). For example, the negative thermal expansion portion 422 and thenonconductive portion 424 can be loaded into a two-chamber die andcompressed to form the negative thermal expansion plate 420.

The negative thermal expansion fuse 400 can be formed by compressing thenegative thermal expansion plate 420 between first metal plate 410A andthe second metal plate 410B (808). For example, the negative thermalexpansion plate 420 can be interposed between the first metal plate 410Aand the second metal plate 420, which can be nickel (Ni) plates having athickness of approximately 0.2 millimeters (mm). Furthermore, thenegative thermal expansion plate 420 interposed between the first metalplate 410A and the second metal plate 410B can be compressed at 60° C.to form the negative thermal expansion fuse 400.

In some implementations of the current subject matter, the negativethermal expansion fuse 400, which can be formed by performing theprocess 800, can be integrated into an electric power system such as,for example, the electric power system 450. Alternatively and/oradditionally, the negative thermal expansion fuse 400 can be coupled toan electric power system via an external connection.

In the descriptions above and in the claims, phrases such as “at leastone of” or “one or more of” may occur followed by a conjunctive list ofelements or features. The term “and/or” may also occur in a list of twoor more elements or features. Unless otherwise implicitly or explicitlycontradicted by the context in which it used, such a phrase is intendedto mean any of the listed elements or features individually or any ofthe recited elements or features in combination with any of the otherrecited elements or features. For example, the phrases “at least one ofA and B;” “one or more of A and B;” and “A and/or B” are each intendedto mean “A alone, B alone, or A and B together.” A similarinterpretation is also intended for lists including three or more items.For example, the phrases “at least one of A, B, and C;” “one or more ofA, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, Balone, C alone, A and B together, A and C together, B and C together, orA and B and C together.” Use of the term “based on,” above and in theclaims is intended to mean, “based at least in part on,” such that anunrecited feature or element is also permissible.

The subject matter described herein can be embodied in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. The implementations set forth in the foregoingdescription do not represent all implementations consistent with thesubject matter described herein. Instead, they are merely some examplesconsistent with aspects related to the described subject matter.Although a few variations have been described in detail above, othermodifications or additions are possible. In particular, further featuresand/or variations can be provided in addition to those set forth herein.For example, the implementations described above can be directed tovarious combinations and subcombinations of the disclosed featuresand/or combinations and subcombinations of several further featuresdisclosed above. In addition, the logic flows depicted in theaccompanying figures and/or described herein do not necessarily requirethe particular order shown, or sequential order, to achieve desirableresults. Other implementations may be within the scope of the followingclaims.

1-10. (canceled)
 11. A fuse, comprising: a negative thermal expansionplate interposed between a first metal plate and a second metal plate,the negative thermal expansion plate comprising a negative thermalexpansion material such that at least a portion of the negative thermalexpansion plate contracts in response to an increase in temperature, thecontraction of the negative thermal expansion plate forming anonconductive gap between the first metal plate and the second metalplate, and the formation of the nonconductive gap disrupting a currentflow through an electric power system coupled with the fuse.
 12. Thefuse of claim 11, wherein the negative thermal expansion plate comprisesa nonconductive material configured to provide structural support. 13.The fuse of claim 12, wherein the nonconductive material comprises apositive temperature coefficient material such that another portion ofthe negative thermal expansion plate undergoes a phase transition inresponse to a temperature exceeding a threshold value, wherein the phasetransition causes the other portion of the negative thermal expansionplate to expand, and wherein the nonconductive gap is further formed bythe expansion of the other portion of the negative thermal expansionplate.
 14. The fuse of claim 12, wherein the positive temperaturecoefficient material comprises poly ethylene, polyvinylidene fluoride(PVDF), acrylonitrile butadiene styrene (ABS) thermoplastic, glassand/or fiber-reinforced acrylonitrile butadiene styrene (ABS), acetal,amber, benzocyclobutene, cellulose acetate (CA), cellulose acetatebutynate (CAB), cellulose nitrate (CN), chlorinated polyether,chlorinated polyvinylchloride (CPVC), ethylene ethyl acrylate (EEA),ethylene vinyl acetate (EVA), fluoroethylene propylene (FEP), fluorspar,CaF₂, gutta percha, nylon molding and/or extruding compound, paraffin,polybutylene (PB), polyamide (PA), polyester, and/or polypropylene (PP).15. The fuse of claim 11, wherein the electric power system comprises acircuit, an electric appliance, an electric generator, and/or an energystorage system.
 16. The fuse of claim 11, wherein the fuse is disposedon an interior of the electric power system.
 17. The fuse of claim 11,wherein the fuse is coupled with the electric power system via anexternal connection.
 18. The fuse of claim 11, wherein the negativethermal expansion material comprises one or more oxides.
 19. The fuse ofclaim 11, wherein the negative thermal expansion material comprises asilicate, a zirconium tungstate, a cyanide, a ruthenate, a siliceousfaujasite, Fe₃Pt perovskite oxides, an antiperovskite, a zeolite, asamarium fulleride, LaCu₃Fe₄O₁₂, an invar alloy, a metal oxide, alow-dimensional material, a metal fluoride, a mechanoresponsive polymer,a porous polyacrylamide, a dibenzocyclooctadiene, and/or apolyacrylamide film containing dibenzocyclooctadiene.
 20. The fuse ofclaim 11, wherein the negative thermal expansion material comprises acomposite of one or more negative thermal expansion materials.